Bulkhead for rigid airships



Aug. 11, 1931. K. ARNS'1'EIN ET AL 1,818,952

BULKHEAD FOR RIGID AIRSHIPS Filed Feb. 2, 1928 gwoanl oz Karl Arnakeim Paul Helms Patented Aug. 11, 1931 STATES PATENT OFFICE KARL ARNSTEIN AND PAUL HIE-LITA, F AKRON, OHIO, ASSIGNORS TO GOODYEAR ZEPPELIN CORPORATION, OF AKRON, OHIO, A CORPORATION OF DELAWARE BULKHEAD FOR RIGID AIRSHIPS Application filed February 2, 1928. Serial No. 251,372.

This invention relates to rigid airships and it has particular relation to bulkheads for supporting the end walls of gas cells in such airships.

, One object of the invention is to provide an improved bulkhead for airships which is adapted to be initially cambered a predetermined degree, and which prevents the bulging of the gas bags of the airship in excess of such degree.

Another object of the invention 1s to provide a bulkhead composedof netting and radially disposed wires so arranged that forces caused by gas pressure acting against the bulkhead initially are distributed uniformly and directly to the supporting structure by the netting before the wires are tensioned.

Heretofore, rigid airships, having inherently rigid polygonal main rings dlsposed transversely thereof, have been provided with bulkheads that were composed of relatively slack wires extending diagonally between the various sides of the main rings. Other known constructions included cord netting connected in the plane of the main ring instead of employing wires. Also, cord nettings have been connected to wires extending between the various corners of the main ring. When the wires, arranged in the manner designated, were secured together at their intersections, the construction was diiiicult to handle and to install, whereas, when, if the wires at theirintersections remained so as to be relatively movable, they were likely to be shifted from their proper position, thereby permitting the gas cells to be caught therebetween and injured. If the bulkheads were constructed entirely of cord netting, it would stretch and, after a limited period of time,

it would likely become distorted and fail to perform its function properly.

Where cord netting was employed in addition to tensioned bracing wires arranged diagonally between the corners of the main e5 ring, the action of the lifting gas w1th1n the gas cells thereagainst, especially when one of two adjacent gas cells became deflated, subected the elements of the ma n rings to com oressiv'e forces which were disadvantageous. ifsfnreeaer, airshipe previoneiy construct edthe polygonal contour of the mainring had relatively few sides and therefore, the area of a section of netting supported by adjacent radial wires was relatively large.

Consequently, such sections were subjected to considerable loads due to gas pressure and were required to be composed of relatively strong and heavy material. The circumferential edge of the netting was fastened only at the inner corners of the'main ring, thus forming catenaries between adjacent corners. Also, the net ing was connected to the bracing wires. Moreover, the catenaries formed along the outer edge of the netting adjacent the corners of the ring left large gaps between the netting and the hull superstructure. Accordingly, there was danger of the gas cells bulging through these gaps and being injured.

The primary purpose of this invention is to obviate the disadvantages of the bulkhead construction described above, by providing a bulkhead in which the advantages of a wire system are combined with those of a cord netting. When wires are tensioned, within their elastic limit, they-do not stretch appreciably and also do not have a permanent elongation after the bulkhead has been bulged. On the other hand, cord netting, intermeshed with wire supports disposed relatively closely together, can be made of light small cords and the relatively small meshes provide a uniform support for the ends of the gas cells.

According to this invention, the bulkhead is composed of a relatively large number of wires installed in relatively slack condition radially within the main rings, while netting is initially installed in taut condition, or at least in such condition that it becomes taut before the wires are subjected to tensional forces. This netting is connected to the circumferential portion of the main ring. The wires are loosely interwoven through the meshes of the netting.

For a better understanding of the invention reference may now be had to the accompanying drawings, forming a part of this specification, of which:

Fig. 1 is a diagrammatiealfragmentary view aireniis having a.

main ring therein, and illustrating portions of a bulkhead mounted therein according to the invention;

Fig. 2 is a diagrammatical fragmentary cross-sectional view taken substantially along the line II-II of Fig. 1;

Fig. 3 is a dia-grammatical fragmentary view, on a larger scale, illustrating in detail the manner of connecting the wires and netting ;of the bulkhead to the airship superstructure; and

Fig. 4 is a fragmentary view, on a larger scale, showing the manner in which the central portions of the netting are connected.

In practicing the invention, a rigid airship hull is provided which I comprises transversely disposed main rings 11, having inner and outer ring -girders 12 and 13, respectively, that are connected by means of longitudinally disposed girders 14. These elements constitute the primary supporting siqae 'structi'ire forlifting gas cells 15 dieposed within the hull. One of the gas cells 15 isshown in broken lines to indicate its position before it is bulged. The main rings are substantially polygonal with respect to 'th'eftran'sverse cross-sectional contour of the hull and 'the corners of the polygons thus defined "correspond substantially to the points of intersection-of the outer rings 13 and the ,lon itndinals 14.

' 'ulkheads it are disposed normally within the main rings 11 'substanti'a'lly along the medial plane thereof, as shown by broken lines of Fig. 2, and serve assupports for the axial end walls of the'contiguousfgas cells. The bulkheads are composedofradial'ly disposed wires 17 connected centrally to a r'el'atively small ring 1'8, and connected at their outer ends 19 by means of Wires 20, in the form ofbridles, to theinner ring girc'lers 12 at the cori ers of the po'lygonal contour thereof, as indicated at 23. It will be observed that each'wire 17 has at least two connecting wires 20 secured to the corners '23 of the ring girder 12. The radial Wires 17 are so installed within the ring 11 that they are not "subjected to initial tension, but they hang relatively leosely or slack in the medial plane thereof. They are not intended to serve as bracing 'wii-es'foi t11e main rings or to support loads applied transversely of the hull, but only to resist forces caused by the lifting gasbulging the gas cells thereaga'inst. v

. A'cor'd netting 2 1, the meshes of which are defined by cords 26 that are connected at intervalsin knots '27, is connected 'at its outer cir'cui'nferential portion to the bridles 20 at the same points I9 "as the Wires 17 are connected thereto. 7 It will be observed that thefcords '26 are disposed at jacute angles with respect tothe wires 17 which arenot positively connectedto the netting,biit they are interwoven loosely through the fineshes "thereof. Since the wires 17 are disposed relatively closely together the meshes of the netting can be distributed properly to provide a uniform support for the ends of the gas cells. By interweaving the wires through the meshes of the netting, the wires are prevented from spreading.

The meshes of netting of ordinary construction would become crowded toward the central por-tionof the bulkhead and, in order to obviate this disadvantage, the meshes of the netting 24 are arranged in zones, the first of which extends from the connections 19 to the location indicated at 28. The second zone extends from the portion 28 to the beginning of the final or inner zone, indicated 29. The number of zones *clepends'upon the sizeof the ring. "The cords of "the netting comprising these zones vary in size and strength. Since the strength of the netting should be uniform in radial directions, 'the larger cords are disposed in the zones nearer the central portion of the bulkhead where fewer meshes are required.

While the netting specified is composed of conventional cords, it is within the scope of this in vention to employ other kinds of 'flexible 'nraterial for this purpose. The modul'us of elasticity of the'wires, of course, is materially greater than that of. the material forming the netting,

T he inner circumferential portion of the netti'ifig 24 is connected by ii'ieans of ropes or cords 30 to 'a central connecting element 33,

wli'ich may be in the form of a ring. l hes'e cords 3 0 are looped throi'igh the ring and, afterbeingtensioned a' predetermined degree, the end portions thereof are secured to form loops by means 'of positive fastening devices 34. The tension of the netting may be varied by manipulating the cords 30 and r the fastening devices 34. Preferably the netting is installed in a taut condition while the wires 17 extend loosely through the meshes thereof. However, the netting may be installed substantially without being ten sioned, or in only slightly tensioned condition in order that the bulkhead may have a predetermined camber away from the medial plane of the main ring before an appreciable resistance is imparted to the bulging forces 'o'fthe gas cells. In any event, it is always .desirable that theforcesfcaused by the gas cells bulging against the bulkheads be re. sisted first by the netting and subsequently by the radial wires as they become tensione'd.

If desirable, certain of "the wires 17 may be extended to the points of connection 23;

andbridles 36, similar to the bridles 20, can

be connected to these points, as well as to the outer corners of them'ain finindi- 'c'atedat 37. This construction provides for 'a greater number of meshes adjacent the inner circumferential portion'of the main ring.

Also the wires 17 may be so installed as to y provide more space between adjacent wires than that indicated by the previously described construction. In this construction, bridles 38 secured, as indicated-at 39 and at 23, connect the netting and wires in substantially the same relation as that previously described. Owing to the considerable length of the sides of the polygonal main rings, it is preferable to provide more than one wire between adjacent corners 23 of the main ring.

From the foregoing description, it will be apparent that bulkheads constructed and arranged as specified protect the gas cells from bulging therethrough, while the advantages of a strong wire bulkhead are retained. Also,

limited movement of the ends of the gas cells is provided for the purpose of properly distributing the loads imposed thereby and without subjecting the main rings to eXcessive compressive forces.

Although only the preferred forms of the invention have been illustrated and described in detail, it will be apparent to those skilled in the art that it is not so limited but that various minor modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What we claim is:

1. The combination with a rigid airship including longitudinals and an inherently rigid main ring, of a uniformly yieldable bulkhead comprising a plurality of wires connected in slack relation radially within and to the main ring and a cord netting installed in taut condition in conjunction with the wires.

2. The combination with a rigid airship including longitudinals and an inherently rigid main ring, of a plurality of wires connected radially within the main ring in slack condition and a netting connected in taut condition in conjunction with the wires, said netting being adapted to stretch when the bulkhead is bulged away fromthe plane of the main ring.

3. The combination with a rigid airship including longitudinals and an inherently rigid main ring forming a hull superstructure, of a uniformly yieldable bulkhead composed of diiferent materials disposed substantiallyin the plane of the main ring and connected thereto, one of the materials having a greater modulus of elasticity than the other material, the material having the greater modulus of elasticity being installed in a materially slacker condition than the other material.

4. The combination with a rigid airship including longitudinals and a rigid main ring forming a hull superstructure, of a uniformly yieldable bulkhead disposed within and connected only to the main ring comprising wires all of which are disposed in slack relation radially with respect to the main ring and a cord netting partially supported by the wires, the strands forming the meshes of the netting being disposed at acute angles with respect to the wires.

5. The combination with a rigid airship having longitudinals and an inherently rigid main ring forming a hull superstructure, of a bulkhead comprising a cord netting con nected circumferentially within the main ring and a plurality of wires radially disposed in conjunction with the netting within the main ring and connected to the main ring, the wires being interwoven relatively loosely with respect to the netting and means connected to the netting for varying the tension thereof radially from its central por tion.

6. The combination with a rigid airship including longitudinals and an inherently rigid main ring, of a bulkhead comprising a plurality of wires disposed radially within the main ring and a cord netting disposed in the plane of the main ring in conjunction with the wires, said netting being arranged in substantially annular zones each having a materially different number of meshes circumferentially and a diflerent size of cord.

7. The combination with a rigid airship including longitudinals and a main ring, of abulkhead comprising a cord netting connected positively only to the circumferential structure of the main ring and a plurality of wires connected radially of the main ring and loosely interwoven with respect to the netting.

8. The combination with an airship including longitudinals and a polygonal main ring, of a uniformly yieldable bulkhead comprising a plurality of wires disposed radially within the main ring and a cord netting arranged in the plane of the main ring in conjunction with the wires, the wires and netting being installed under materially diiferent degrees of tension, and means forconnecting the wires only to the inner corners and to the outer corners of the main ring.

9. A uniformly yieldable bulkhead for airships comprising a cord netting having cords of greater strength at the inner portion than the outer portion thereof, a plurality of wires radiating from a central portion of the bulkhead and interwoven loosely among the meshes of the netting, and common connecting means for the wires and netting at the other portions thereof, the netting becoming taut before the wires when the bulkhead is tensioned radially.

In witness whereof, we have hereunto signed our names.

KARL ARNSTEIN. PAUL HELMA. 

